Seasonal changes in sea ice optical properties during fall freeze-up

摘要: Abstract During the seasonal transition from summer to winter conditions, a sea ice cover undergoes profound transformation. As air temperature drops, cools, brine volume decreases, melt ponds freeze, new forms in areas of open water, and surface becomes snow-covered. There is corresponding change optical properties with albedos increasing transmittances decreasing. part Coordinated Eastern Arctic Experiment (CEAREX), measurements spectral albedos, reflectances incident irradiances were made at visible near-infrared wavelengths (400–1100 nm) during fall freeze-up. In general, increased as freeze-up progressed, increase being most pronounced shorter wavelengths. The greatest temporal changes occurred freezing lead where, only few days, 0.1 for water 0.9 snow-covered young ice. evolution transmitted radiation field under was estimated using two-stream, multilayer radiative transfer model conjunction observations morphology thickness. Transmission decreased dramatically due cooling, snowfall, declining solar irradiances. Light transmission through two orders magnitude greater than multiyear